Power control



Feb. 6, 1951 N, R. KRAUSE 2,540,894

POWER CONTROL Filed Feb. 26, 1945 52 5 7 INVENTOR.

.53 fl 55 07M 54 if 50 fimwn/ 3 m 132mm.

Patented Feb. 6,

POWVER CONTROL.

Norman R. Krause, Racine, Wi's.,. assignor to J I. Case Company, Racine, Wi's., a corporation of Wisconsin Application February 26, 1945,. Serial No. 579,858

' ample, it is necessary that the mechanical expedients be as simple and inexpensive as. possible, both because of the advantages of low first cost and the. distance, from a. repair shop at which these devices are. commonly used. The present device serves the purpose of satisfactoril maintaining a necessary tension in, a simple belt drive. It. also may act. as av clutch or power stop control of. very simple nature and which maybe very readily repaired if necessary after long service. Belt drives are sometimes troublesom in that the belts will not run accurately on the pulleys but tend to. run to. one side or to run off.

Further objects. of the invention accordingly are. to, provide a devicewhich. will tighten. a belt repeatedly to a predetermined tension. without careful attention on. the. part of the. operator; which will compensate for Wear or other deterioration through. a generous range; which may be readily adjusted to restore a predetermined tension; which, may assist in guiding a belt to run properly on its pulleys and which is suitably adjustable for this purpose. The manner in which. these objects are accomplished will be apparent from. the. following specification and accompanying drawings in which a suitable embodiment of the. invention is shown. However, it is to be understood that the invention, is not limited to the details disclosed but includes all such: variations and modifications as. fall. within the spirit of the invention as herein expressed. Figure 1f a. side. elevation of a typical em? bodiment. of the. invention as applied to a har vester threshen Figure 2. is a. plan view of the. same. Figure 3 is an axial sectional view taken sub:- stantially on the. line 33 of Fig. 1.

I As seen in Fig. 1,. the. device is. applied to a combination harvester thresher, a. portion. of the frame of" which is indicated generally as H, but it is to be. understood that many of the principles of the. inventionv are, applicable to. other machines, a, harvester thresher being considered. as typical. The machine has anengine generally designated as E afan F anda drawbar D. FanF has a shaft. 5 which in the present instance cons stit'utes the, main. power input shaft of the ma chine and, whichis driven. from engine E, the transmission of power between the two being 2 governed. by a control. generally designated as. C. Manipulation of. control C can. be used to start and, stop. shaft 5 at any time that engine E. is running.

Engine E. has a main output or. crankshatt 6 carrying a. pulley 1 preferably, although not necessarily, oi the flanged type and which drives through a. belt 8-, a pulley 9. fixed. on shaft. 5. Pulley 1 being. flanged, engine E may be (driving pulley 1-) with belt 8 loose enough. to allow tree rotation of pulley L without driving pulley 9. For driving pulley 9, belt 8 must be tightened and this. is accomplished by an idler pulley it carried by an arm. it pivoted. on afulcru-m or pin I 2. carried in the present instance by a boss or bracket l3, fixed with or forming a part of engine E1. Swinging of arm ll toward and from belt 8,. will. accordingly cause pulley H] to tighten or loosen. belt 8 as desired- Such. swinging of arm [I is accomplished from above mentioned control. C For this purpose, arm. H is. connected. by suitable means, such as a. link. [4. pivoted at. L5. to. arm H, with an. arm I'G injthe. present. instance. rigid with. a rock shaft 11 (see also. Fig. 2.) a suitable. pivot pin. i8; connecting link l4. to arm.|6.. I

Rock shaft. ['1 is carried in suitable. bearings I9 and; 20 on frame. H and has an arm 2 I. pivoted at 22 to a rod 23 connected through a spring generally designated. as; 24. with. afitting Z5 pivoted. at. 26; with a lever 21 constituting in the present. instance above; mentioned control Rocking lever C. to theleft, as seen in Fig. 1-, will pull on rod 23,, rock shaft 11 in a counterclockr wise direction and. through link l4, press idler pulley IDv against belt 8.. Reverse motion of lever. 21 will loosen belt 8 and. allow engine E to run free. without. driving shaft; 5..

Lever. 21' is. fulcrumed at 2-8 toa bracket 29;. bolted as, at 30 or otherwise suitably fixed to; drawbar D or. any convenient part of: themachine and swings. adjacent a quadrant 3i forming. in the. presentv instance apart of bracket 2.9.2. Quadrant 3| is provided. preferably with a single; detent notch. 32 which; is engaged by any suit able detent. mechanism as 33; slidable in a guide 34 and. actuated by a handgrip portion. 35- fulcrumed at 36 to-lever 21. Detent 33 is pivoted. at: 31 to. grip. 35' and a. spring. 38: serves to: continuously urge grip 35 away from lever 2-1 and ac:- cordinglyto urge detent 33 into contact. with quadrant. 31. Thus, as, will be; apparent,. when lever 2-1 is pulled to the left, detent 33 will. drop into notch .32. and fix lever; 2-1: in a. definite pre.-- determined position. This corresponds to the normal running position of pulley I0. Releasing of detent 33 by actuation of grip 35 permits lever 21 to move to the right and pulley ID to move away from belt 8. A stop 39 is provided on quadrant 3| to limit this movement.

A stop 40 is also provided if desired, to limit travel of lever 21 to the left.

The tension in belt 8 should be controlled so as not to exceed a certain maximum and above mentioned spring 24 is provided to insure proper conditions being attained. In the present instance the device comprises a coil spring of common or well-known type 4| having an end extension 42 anchored in above.mentioned fitting 25 in any suitable manner as by one or more lock nuts 43. The other end of spring 4| has an extension 44 which is maintained in rigid engagement with above mentioned rod 23 by means of a clamp 45 encircling rod 23 and extension 44. Clamp 45 is closed on members 23 and 44 by means of a bolt 46 and extension 44 has an upturned portion 41 which may engage the edge of clamp 45 to positively prevent withdrawal of extension 44. With bolt 46 loosened, the several parts may be fixed so that substantially exactly the right tension Will result in belt 8 when detent 3 is engaged in notch 32. As will now be apparent, spring 4| will be somewhat extended under these conditions and will exert a continuous resilient pull on rod 23 so as to maintain the desired pressure of idler pulley l against belt 8. Slight changes in the length of belt 8, weaving of the machine frame, and such disturbances of "the mechanism will be compensated by extending or collapsing of spring 4| so that the tension of belt 8 will be automatically maintained within the desired limits.

Belts such as 8, particularly when run with comparatively short centers, sometimes do not track properly on the pulleys and corrections in alignment are difficult to secure because the shafts are often connected to numerous other drives and shifting of the shafts is therefore not practical. In the present instance, an expedient hasbeen devised for influencing the running of belt 8 and which is effective to correct the effect of any such minor misalignment or to correctly align pulley Ill in the event of any manufacturing variations in engine E or bracket l3, or other parts.

' As best seen in Fig. 3, arm H is bifurcated and has portions 48 and 49 between which pulley is disposed. Pulley II] has a hub portion 50 iournaled in the present instance on roller bearings of suitable or well-known type on a pin 52- supported in portions 48 and 49. Pin 52 has a shoulder 53 which is urged against a washer 54 by a nut 55 engaging a bushing 56, washer 54 and bushing 56 being forced toward each other on opposite sides of portion 48, so as to clamp pin 52 rigidly in place in arm At the other end, pin 52 has a shoulder 5'! defining a reduced portion 58 engaged in a bushing 59 supported in above'mentioned portion 49. In this manner, pin 52 is supported at its ends in arm Bushings 56 and 59 are eccentric, that is to say the bushing's have bores which are offset relatively to the center line of the outer diameters of the bushings. Bushing 56, for example, is engaged in a bore 60 in portion 48 but pin 52 is supported eccentrically relatively to bore 66. In similar manner, bushing 59 is engaged in a bore 6| and supports reduced portion 58 eccentrically of bore 6|. bushings 56 and 59 within bores 68 and 6| 'will therefore cause displacement of the ends of pin 4 1 52 and change the relation of pulley II] to arm Thus if belt 8 has a tendency to run to one side, suitable shifting of bushing 56 or bushing 59, or both, can be resorted to, to change the angular relation of pulley ID to belt 8 which will normally correct the running of the belt. Bushing 59 is maintained in place on portion 58 in any suitable manner as by a pin 62. Lubrication for bearing 5| is supplied by means of a pressure fitting 63 of suitable or well-known type, a passageway 64 leading to bearing 5|. Hub 50 is provided with grease retainers of suitable type 65 and 66. Since hub 56 is closed, sufficient grease pressure might inadvertently be built up to displace either or both of grease retainers 65 and 66. For this reason, a passageway 6'1 is provided, in the present instance in pin 52 and leading outwardly through portion 58. Excess grease forced in through fitting 63 will escape through passageway 61 without generating excessive pressure in hub 58. Also, grease issuing from passageway 61 will be an indication that bearing 5| is adequately lubricated.

From the above description, it will be apparent that devices and expedients have been provided for the accomplishment of the objects set forth, actuation of control C serving to tighten or loosen belt 8 and thereby to control the opera-, tion of driven shaft 5 at will. Furthermore, belt 8 will be invariably brought to the correct tension and compensation will be made for ordinary slight variations in dimensions of the parts. In the event that controlC is inadvertently moved too far there will be no excessive stress introduced into belt 8 since spring 4| will merely stretch somewhat beyond its normal condition but without materially increasing the pressure on pulley l0. Alignment of arm with pulley I is assured by the mounting of bracket 3 and pin l2 directly on engine E. Furthermore, since link 4 is connected with arm I in line with the middle of pulley It], the pressure of the link has no tendency to twist arm II and the arm therefore remains in proper position relatively to belt 8. Furthermore, inaccurate runnin of the belt may be corrected by suitable adjustment of the bushings 56 and 59. The device isexceedlngly simple and durable and easily repaired and it dispenses with the use of a highly organized clutch commonly necessary for control of power 'in similar installations. V

The above being, a complete description of an illustrative embodiment of the invention, what is claimed as new and desired to be secured by' stantially parallel axes, a belt tightener including Turning of stantially parallel to each other, a belt connect-' ing said pulleys; an arm, a, pin carried by the arm, an idler pulley journaled on the pm, said arm being swingable so as to shift said idler pulley toward and from the belt for tightening and loosening the same, means for so swinging the arm, and adjustable means connected between an end of the pin and the arm for shifting the pin relatively to the arm to change the angle of the pulley relatively to the belt and to the axes of the driving and driven pulleys for affecting the running of the belt to correct said running in the event of inaccurate tracking thereof.

3. In a linkage for controlling a belt tightener, the combination of a shiftable belt tightening idler pulley, a resilient deformable member connected to said shiftable belt tightening pulley in position to urge said pulley yieldingly in a belt tightening direction, and a control for said linkage connected with said resilient deformable member and adapted when moved in one direction to cause said resilient member to so move said idler pulley, and detent means constituted to maintain said control in a predetermined position wherein said resilient member is deformed a predetermined amount, said detent means being releasable for shifting of said control into a position wherein said resilient member is relieved from deformation, and said idler pulley is relieved from pressure in a belt tightening direction.

4. In a linkage for controlling a belt tightener, the combination of a shiftable belt tightening idler pulley, a resilient deformable member connected to said shiftable belt tightening pulley in position to urge said pulley yieldingly in a belt tightening direction, and a control for said linkage connected with said resilient deformable member and adapted when moved in one direction to cause said resilient member to so move said idler pulley, and detent means constituted to maintain said control in a predetermined position wherein said resilient member is deformed a predetermined amount, said detent means being releasable for shifting of said control into a position wherein said resilient member is relieved from deformation, and said idler pulley is relieved from pressure in a belt tightening direction, and said resilient member being adjustable to vary the pressure exerted on said pulley when said control is in said predetermined position.

5. In a power control the combination of a driving pulley and a driven pulley having substantially parallel axes, a belt tightener including a swinging arm having a pivotal support, a pin carried by said arm and spaced from said pivotal support, an idler pulley journaled in relation to said pin, and a supporting device interposed between an end of said pin and said swinging arm and adjustable relatively thereto to shift said end of said pin in relation to said arm for changing the angle of the pin and pulley relatively to the arm and axes of the driving and driven pulleys for correcting the running of the belt in the event of inaccurate tracking thereof.

6. In a power control the combination of a driving pulley and a driven pulley having substantially parallel axes, a belt tightener including a swinging arm having a pivotal support, a pin carried by said arm and spaced from said pivotal support, an idler pulley journaled in relation to said pin, and a supporting device interposed between an end of said pin and said swinging arm and adjustable relatively thereto in any direction to shift said end of said pin in relation to said arm for changing the angle of the pin and pulley relatively to the arm and axes of the driving and driven pulleys for correcting the running of the belt in the event of inaccurate tracking thereof.

NORMAN R. KRAU'SE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 229,841 Rinehart et a1. July 13,, 1880 256,913 Mills Apr. 25, 1882 258,242 Merritt May 23, 1882 420,476 Thayer Feb. 4, 1890 1,580,308 Lawson Apr. 13,. 1926 

